quiche: Add console command to change lane control signal
quiche: Add console command to change lane control signal

There is a gpio signal controlled by the EC to communicate to the MST
hub if 2 lane or 4 lane DP should be trained. The lane control GPIO
signal must be set when the MST is in reset. This CL adds a console
command 'dp_lane' to execute this sequence.

BUG=b:183288657
BRANCH=None
TEST=verified lane control is low for 'dplane 4' and high following
'dplane 2'

Signed-off-by: Scott Collyer <7d40b3eb9e17bf55d972074a5e77a7ea4159f9dd@google.com>
Change-Id: I65d197ad55e86bba9b9ea5374c89cc6505b1100f
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2682788
Reviewed-by: Diana Z <cb2016afc7183e5356c690dc63b4ba817470501a@chromium.org>
Commit-Queue: Scott Collyer <7d40b3eb9e17bf55d972074a5e77a7ea4159f9dd@chromium.org>
Tested-by: Scott Collyer <7d40b3eb9e17bf55d972074a5e77a7ea4159f9dd@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec